@m3rashid/dsa-js/structures/queue.js

A data-structures and algorithms library for node and browser written in typescript. Inspired from C++ standard library

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.test = exports.Queue = exports.QueueNode = void 0;
class QueueNode {
    constructor(data) {
        this._data = data;
        this._next = null;
    }
}
exports.QueueNode = QueueNode;
class Queue {
    constructor() {
        this._front = null;
        this._rear = null;
        this._size = 0;
    }
    enqueue(data) {
        const node = new QueueNode(data);
        if (this._front === null) {
            this._front = node;
            this._rear = node;
        }
        else {
            if (!this._rear || !this._rear._next)
                throw new Error('No Queue found');
            this._rear._next = node;
            this._rear = node;
        }
        this._size++;
        return true;
    }
    dequeue() {
        if (this._front === null)
            throw new Error('No Queue found');
        this._front = this._front._next;
        this._size--;
        return true;
    }
    front() {
        if (this._front === null)
            return null;
        return this._front._data;
    }
    rear() {
        if (this._rear === null)
            return null;
        return this._rear._data;
    }
    isEmpty() {
        return this._size === 0;
    }
    size() {
        return this._size;
    }
    print() {
        let current = this._front;
        let str = '[';
        while (current) {
            str += current._data;
            if (current._next)
                str += ', ';
            current = current._next;
        }
        str += ']';
        return str;
    }
}
exports.Queue = Queue;
const test = () => {
    const queue = new Queue();
    queue.enqueue(1); // [1]
    queue.enqueue(2); // [1, 2]
    queue.enqueue(3); // [1, 2, 3]
    queue.enqueue(4); // [1, 2, 3, 4]
    queue.enqueue(5); // [1, 2, 3, 4, 5]
    queue.dequeue(); // [2, 3, 4, 5]
    queue.dequeue(); // [3, 4, 5]
    queue.dequeue(); // [4, 5]
    console.log(queue.front()); // 4
    console.log(queue.rear()); // 5
    console.log(queue.isEmpty()); // false
    console.log(queue.size()); // 2
    console.log(queue.print()); // [4, 5]
};
exports.test = test;